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Introduction/purpose: This study investigates the seismic response of longspan continuous deck truss bridges under the effect of near-fault vertical ground motions. The primary objective is to assess how near-fault vertical seismic excitation affects the structural safety and performance of these bridges. By exploring the nuanced dynamics induced by near-fault vertical motions, the research aims to improve the understanding of the vulnerabilities and challenges faced by long-span continuous deck truss bridges during seismic events. Methods: To achieve this objective, the truss bridge was subjected to a series of ground motions, representing natural seismic events. The seismic response of the bridge was investigated by applying the linear time history method to the 3D finite element model. This analysis focused specifically on the evaluation of base shear and displacement. The analysis was extended to include the seismic performance of truss structures. The comparison between the bridge responses with and without consideration of the vertical component of ground motion was made to clarify the effect of vertical excitation. Results: The results show that there is a significant contribution of vertical excitation, particularly concerning the internal force in the truss elements, where it exceeded 60 % during a severe earthquake, and consequently increased the demand-to-capacity ratio in most elements of the truss bridge structure. Conclusion: For structural engineers and designers, the results of this research suggest that neglecting to include the vertical ground motion component in the analytical assessments of this type of bridges can lead to a greater degree of uncertainty and risk, particularly in near-fault regions.

Introduction/purpose: Stainless steels have excellent corrosion resistance and adequate mechanical properties. However, their use in aggressively hydrogenated environments in the energy industry causes a loss of ductility. This work studied the effect of hydrogen on the mechanical behavior of the DINX15CrNiSi25.21/AISI310 austenitic stainless steel loaded in an aqueous solution of purely sulfuric acid H2SO4 at 1N at room temperature during tensile testing. Methods: Experimental characterization techniques are applied to standardised machining-manufactured tensile specimens which underwent a series of heat treatments ranging from quenching at 1050°C for 35 minutes to tempering at 680°C for 30 minutes. This is accompanied by a succession of immersions of these samples by cryogenic quenching cycles at -196°C for a duration of 1 hour. The hydrogen was electrolytically loaded in a Pyrex glass cell for various loading times, ranging from 1h00 to 15h00, with a step of 2h00. Results: The results showed a reduction in mechanical properties and plasticity. The electrochemical method confirmed the material's sensitivity to hydrogen embrittlement, calculating the embrittlement criterion EI (%). This method indicates a rapid increase in values depending on hydrogen loading times, with a maximum value of 41.60%. Conclusion: The study highlights the negative impact of hydrogen on the mechanical properties of AISI310 stainless steel, emphasising the need for reduced hydrogen exposure in steel applications.

Agglomeration and poor dispersion of reinforcements are common problems in conventional composite fabrication techniques, especially in hybrid composites. This study presents a novel technique, sequential reinforcement addition method combined with optimized ball milling, to produce copper (Cu) matrix composites reinforced with silicon carbide (SiC) and multi-walled carbon nanotubes (MWCNTs). By carefully controlling the milling parameters and introducing reinforcements sequentially, the study demonstrates substantial improvements in the mechanical, thermal, and electrical properties of Cu-based composites. The Cu+MWCNTs/SiC composite fabricated through this method exhibited a notable relative density of 98.88%, alongside a significant increase in surface hardness to 104.78 HV. Additionally, thermal conductivity improved by 16%, reaching 390 W/m·K, while electrical conductivity showed an 8.5% enhancement, achieving 17.53 × 105 S/m. The wear rate of the composite was reduced by 15%, attributed to the formation of an effective tribolayer that significantly enhances wear resistance, contributing to the overall durability of the material.

This study proposes a novel iron wire activation method for electroless Ni-P plating on 6H-SiC substrates, offering a sustainable alternative to traditional metal activation techniques, focusing on the surface roughness effect on the microhardness and Ni-P plating efficiency of 6H-SiC substrates. This experimental approach reveals insights into the relationship between substrate morphology and plating characteristics. It is found that the plating thickness (33.82 μm) of the non-polished substrates closely matched the expected (33.26 μm), with a deposition rate of 6.65 μm/h, which underscores the precision regulation of the plating process. In contrast, despite the faster deposition rate of 9.20 μm/h of the polished S500 substrate, it exhibited a minor thickness discrepancy, suggesting a saturation point in the deposition dynamics on fully polished surfaces. The research additionally sheds light on the adhesion characteristics of the plated layers, particularly emphasizing the role of surface roughness. Remarkably, non-polished substrates demonstrated better adhesion, categorized as HF3, indicating a significantly stronger bond compared to the polished substrates, which were categorized as HF4 to HF6. This distinction in adhesion categories underlines the critical influence of substrate morphology on the quality of the Ni-P layer's adherence.

The dynamics of a two-wheeled vehicle represent a higher level of complexity, with a high variety of rider practices, peculiarly during the bend-taking maneuver. This complexity is one reason why research on motorcyclists’ practiced trajectories is limited compared to cars. Another reason is the low representation of motorcycles in the land motor vehicle fleet.The dataset was collected within the framework of the French ANR research project VIROLO++. The objective was twofold. One concerns the analysis of the interactions between a rider and the motorcycle during a bend-taking maneuver. The second aims at studying the precise trajectory of a motorcycle.Multi-sensor instrumentation of a motorcycle (Honda CBF1000) has been achieved for precise trajectory reconstruction as well as the analysis of the interactions between the rider and the motorcycle during a ride. Real experiments were conducted on the “La Ferté Gaucher'' racetrack. The collected data include the precise location and attitude of the motorcycle and rider. Several sensors providing redundant data have been embedded to validate measurements. Two RTK GPS receivers were installed at the rear of the motorcycle to provide ground truth. A preliminary analysis was performed to validate the consistency of the dataset and the relevance of the sensors according to the aimed study.

Introduction/purpose: The dynamic analysis of a seismic response of a concrete vault dam is a complex problem in which the representation of the behavior of the material requires some form of a nonlinear model, especially if the concrete is subjected to a significant stress load of the ground. In the case of large movements of the latter, large cracks may form in some areas of the dam, especially at the base of the dam and near sudden changes in geometry. Methods: This analysis was based on a numerical simulation of the dynamic effect. This work was carried out using the finite element method with the ANSYS 12.1 program. The dam was modelled in two dimensions. Four types of analysis were performed: static analysis, modal analysis, seismic analysis under excitation of two accelerograms (Asnam 1980 and Boumerdes 2003), and spectral analysis. Results: This analysis showed the vulnerability of the Brezina dam to the Boumerdes earthquake with high stresses at the base of the structure. Conclusions: Based on this study, it was concluded that if the Brezina dam suffers an earthquake of a greater intensity than that of Boumerdes, this will cause structural damage and cracks that will compromise the dam's watertightness as well as its durability.

The aim of this study is to examine the effect of substrate surface roughness on the deposition and adhesion properties of electroless Nickel-Phosphorus (Ni-P) plating on 6H-SiC substrates, which is a typical mold material for Precision Glass Molding (PGM). This research investigated the impact of surface roughness at different levels. These levels range from polished surfaces with Ra∼58 nm to non-polished surfaces with Ra∼813 nm, affecting both the electroless Ni-P plating process and the quality of the resulting layers. The study reveals that the initial roughness of the substrate significantly influences the final surface profile of electroless Ni-P plating. This is evidenced by the highest roughness of approximately Ra∼1.32 µm observed on the most uneven substrate. Conversely, substrate characterized by an initial roughness of Ra∼160 nm has a reduced post-plating roughness of Ra∼583 nm and contribute to the smoothness of surface. While the observed surface morphology indicates a decrease in the deposition rates. Additionally, the Rockwell C indentation tests indicate that substrates characterized by lower roughness are susceptible to adhesion difficulties, particularly in the form of peeling at the plating-substrate interface.

The current work investigates the effects of drilling parameters on hole quality, including delamination and circularity, produced in hybrid composite materials consisting of neat glass fibre (NG) and hybrid glass fibre/Al-wire mesh in two distinct sequences, the first one being with Al-mesh in the outermost layers (AG) and the other with Al-mesh in the central layer (GA). The operation's process parameters are feed rate (F = 20, 40, and 60 mm/min), spindle speed (N = 1000, 2000, and 3000 rpm), and drill point angle (Ɵ = 90°, 120°, and 135°). Taguchi's L9 orthogonal array is used for the study. The optimal levels and effects of the process parameters were determined. Gray relational analysis (GRA) was employed to examine the complicated interactions influencing the results and ANOVA was used to evaluate the influence of process parameters. The results indicated that for all specimens, push-out delamination was more severe than peel-up. Circularity is minimized by using N = 3000 rpm, F = 20 mm/min, and Ɵ = 90°. At speed (N) of 3000 rpm circularity reduces by 83.5% and 76.5% compared to 1000 or 2000 rpm, respectively. Compared to other specimens, AG-specimen produced minimal delamination and circularity by an average of 6% and17.38%. The results of the confirmation test and regression model provide good agreement between the experimental and predicted results.

Introduction/purpose: Geosynthetic materials have been successfully used for soil reinforcement to improve bearing capacity. In this article, geotextiles are used as tension material for the reinforcement of a mixture based on dredged sediment from the Cheurfas dam (Mascara) and quarry sand. Methods: Immediate bearing index tests were carried out in the laboratory to study the mixing behaviour, and the three-point bending flexural test was carried out on prismatic specimens to study the traction capacity of the mixture. Mixture samples are selected and tested without reinforcement. Then, by placing one, two and three layers of geotextile at a certain depth of the sample, the effects of a number of layers and type of geotextile and geogrid on increasing the bearing capacity of the mixture are discussed. Results: The results of these tests show that the bearing capacity of the samples reinforced by geotextile and geogrid is increased compared to that of the unreinforced samples. Based on the results obtained from ProctorIPI, their values do not permit the movement of construction machinery during the construction of pavement layers. The Immediate Bearing Index values are found sufficient for pavement layers. Geotextile introduction increases traction strength and improves stress distribution on soil samples, with the effect being significant for woven geotextile blends. Conclusion: All things considered, the results point to the possibility of using reinforced local soils as an affordable and practical option for building pavements. To guarantee long-term performance and optimise building methods, more research is advised.

Recently, there has been much scholarly research on the applications of CNTs in various fields which can be attributed to their outstanding properties. For that matter, machining processes as the backbone of manufacturing technologies have also benefited greatly from the introduction of CNTs. However, there is a lack of papers that provide a holistic overview on potential applications, which impedes focused and robust research in their application. In this work, after providing an outline of the methods used in increasing the productivity of machining processes, we will review the ways in which CNTs, known for their remarkable mechanical, chemical, electrical, and thermal characteristics, enhance the productivity of machining processes. We emphasize fit-for-purpose applications to determine the fate of CNTs use in machining processes. We examine the applications of CNTs in enhancing the mechanical characteristics of cutting tools, which include increased wear resistance, strength, and thermal conductivity, thereby extending tool life and performance. Additionally, this work highlights the application of nanofluids in MQL systems, where CNTs play a crucial role in reducing friction and enhancing thermal management, leading to reduced lubricant usage while maintaining cooling and lubrication effectiveness.

Introduction/purpose: Concrete, mortar, and cement pastes are materials that have become central in various fields of construction, structures, and civil engineering. About 7 billion cubic meters of concrete are implemented. Concrete is generally considered a homogeneous material, but that is not always the case given its rheological behavior, which can be due to heterogeneous phenomena of segregation and bleeding. Methods: The study tested a concrete column's physical and mechanical characteristics and deformation in elevation. The tests included measuring absolute and apparent density, porosity, capillary absorption, permeability, speed of propagation, compressive strength, and static and dynamic modulus of elasticity. For this purpose, the standards of non-destructive testing (sclerometer, ultrasound, etc.) were used to take the average of a series of points located at different levels of the element to be tested. Results: The results indicate that changes in the column's height affect its physical and mechanical properties, either increasing or decreasing them (such as porosity, absorbency, permeability, compressive strength, and the static and dynamic modulus of elasticity). These changes are influenced by various factors, including the inherent properties of the concrete implementation (such as vibration and curing) and the climate conditions during construction. Conclusion: The findings of this study emphasize the importance of a nuanced approach to testing and evaluating variations in concrete properties by taking into account the multifaceted impact of changes in column height.

In this study, Mg-Ti-SiC composite powders with varied micron and nano silicon carbide (SiC) particle sizes were fabricated utilizing the ball milling technology at various milling times. The effect of reinforcement particles sizes and milling time on the morphology and microstructure of the magnesium composite powders was characterized. Then, we developed a machine-learning model based on Adaptive Neuro-fuzzy Inference System (ANFIS) modified with termite life cycle optimizer to predict the crystallite size of the produced composites. The average particles size in all composites including micron SiC (µSiC) and nano SiC (nSiC) always decreased with increasing milling time and SiC content, and the most optimal reduction in particle size was achieved after 16 h of milling for both configurations, which were 5.12 µm and 1.96 µm, respectively. Changing reinforcement particle size from micron to nano caused the peak intensities of Mg and Ti more decreased and phases Ti5Si3 and TiC were observed after milling for 16 h in ND composite powder. With increasing milling time in Mg-25 wt% Ti-5 wt% µSiC, the crystallite size decreased from 31 nm to 13.62 nm after 1 h and 32 h milled, respectively. The most optimum reduction in crystallite size occurred in the composite powders including nSiC, in which crystallite size decreased to 13.35 nm. The developed Machine learning model was able to predict the evolution of the crystallite size of the produce d composites with very good accuracy.

The journal retracts the article, “Ceftriaxone and Melittin Synergistically Promote Wound Healing in Diabetic Rats” [...]

Abstract Mandibular retrognathia (C2Rm) is one of the most common oral pathologies. Acquiring a better understanding of the points of impact of C2Rm on the entire skull is of major interest in the diagnosis, treatment, and management of this dysmorphism, but also permits us to contribute to the debate on the changes undergone by the shape of the skull during human evolution. However, conventional methods have some limits in meeting these challenges, insofar as they require defining in advance the structures to be studied, and identifying them using landmarks. In this context, our work aims to answer these questions using AI tools and, in particular, machine learning, with the objective of relaying these treatments automatically. We propose an innovative methodology coupling convolutional neural networks (CNNs) and interpretability algorithms. Applied to a set of radiographs classified into physiological versus pathological categories, our methodology made it possible to: discuss the structures impacted by retrognathia and already identified in literature; identify new structures of potential interest in medical terms; highlight the dynamic evolution of impacted structures according to the level of gravity of C2Rm; provide for insights into the evolution of human anatomy. Results were discussed in terms of the major interest of this approach in the field of orthodontics and, more generally, in the field of automated processing of medical images.

This article discusses the correlation between the microstructural and mechanical changes in the dual-matrix Al-Ni/SiC composites processed by Accumulative Roll Bonding (ARB) technique. Three different SiC concentrations, 1, 3, and 5% were considered to reinforce Al and Al-Ni dual-matrix composites. ARB process was applied up to 7 cycles to manufacture a composite with homogenous dispersion of the three phases. The results showed that the presence of Ni layer between Al and SiC particles enhanced the dispersion of SiC in the matrix, which positively affect the mechanical strength. The maximum tensile achieved was 257 MPa for composite containing 3 % SiC after 7 ARB cycles compared to 37.2 MPa for the AA1050. Increasing SiC content reduces the adhesion between Al and Ni layers, which reduces the elasticity of the composites. However, for the composites with 5% SiC, after 3 ARB cycles, the strength was reduced due to the cracking of the Ni layer caused by the stress concentration around the SiC particles. The hardness values of the ARBed AA1050, AA1050-Ni, and AA1050-Ni/5 wt% SiC are 85.5, 93.5, and 109.7, respectively, after 7 ARB cycles. In terms of strength, the samples with 3% SiC content showed the optimum stress enhancement with minimum reduction in the elongation, which achieve a compromised response for many applications.

Blood flow analysis plays an essential role in understanding cardiovascular health and disease. An accurate mathematical modeling is necessary in context of representation of arterial domains and blood flow to learn about the intricate blood dynamics. In this paper we concentrate on the mathematical representation of the geometry of the blood artery and find numerical solutions with mild to severe degree of stenosis. Blood dynamics has steady state, in-compressible and laminar nature. The shear thinning non-viscous effects of blood are assumed to obey Carreau model. Fluid flow is based on coupled Navier-Stokes equation in three dimensions and is simulated with finite volume approach over hexahedral elements. Application of a constant mass flow rate at the inlet of the artery results in a number of observations to analyze. It is found that with increasing the severity of stenosis, blood velocity becomes higher in stenotic region, pressure drop along the arterial domain is increased and shear stresses exerted by blood on walls of artery are increased.

Accumulative Roll Bonding (ARB) is one of the main techniques to manufacture nanocomposites, however, due to the large number of parameters that control this process, its application is relatively expensive. The present work considers a simple response surface methodology to study the interaction effect between the selected ARB parameters on the tensile strength and the hardness of the ARBed composite sheets. We investigated the characterization, modeling, and numerical optimization of the accumulative roll-bonded (ARBed) AA1050 composite sheets produced using a number of passes ranging from 1 to 7 and reinforced with different SiC content (0, 1, 3, and 5 wt%). The effect of the number of passes and SiC content on the microstructure, phase analysis, tensile, and hardness properties have been investigated for the ARBed sheets and their composites. Also, the fracture surface of the tensile-tested specimens was studied using SEM analysis. Numerical optimization was conducted using the developed model to determine the optimum parameters of the ARB process in the designed experiments. The modelling analysis results confirm the significance of the applied ARB parameters on the properties of the ARBed sheet composites. The numerical optimization analysis indicates the optimum ARB factors are 7 passes and 3.2 wt% of SiC content to produce an AA1050/Ni-SiC composite sheet with 249.2 MPa tensile strength and 107.8 HV hardness.